The earliest account is George Waldron's, in his Description of the Isle of Man of 1744, who set the water bull among the prodigies of nature he was convinced of the truth of. It was an amphibious creature so like a bull that many people, seeing him in a field, had not distinguished him from the natural kind, and the cows had no instinct to avoid him, though what they conceived by him never had life or any due formation but was a rude lump of flesh and skin without bones, seldom brought forth without the death of the cow. A neighbour of Waldron's who had lost several cows to it set a man to watch, and when word came that a strange bull was among the cows he called a good number of lusty men armed with poles and pitchforks. They ran at the bull together, but he was too nimble, and after tiring them over mountains and rocks and a great space of stony ground he took a river and dived down into it, showing his head above water now and then as if to mock their skill. Waldron heard of another man who had more cunning and shot one with a brace of bullets as it was going into the river.

Joseph Train, in 1845, said the belief was not yet extinct. A few years before, the farmer of Slieau Mayll in Onchan, coming home from worship one Sunday evening, had seen at the garee of Slegaby a wild-looking animal with large eyes sparkling like fire cross the road before him and go flapping away, which he knew for a tarroo-ushtey because his father had seen one at nearly the same place, and he broke his walking stick over its back, so lazy was it to get out of his way. The farmer's brother, going to the fold very early one June morning at Lhanjaghyn, saw a water bull outside it, and the bull within broke through the fence and ran at it roaring and tearing up the ground, but the tarroo-ushtey scampered off unconcerned, leapt over a precipice into deep water, swam about a little as if amusing himself, gave a loud bellow and disappeared. A. W. Moore printed both accounts in 1891, with the Manx word, and gave the old Fenodderee song that calls down the spotted water bull and the Glashtin on an enemy to throw him like a bolster against the wall.

John Rhys, collecting in 1891, was told by a man from the Ayre that there used to be a tarroo ushtey between Andreas and the sea to the west before the ground was drained, and an octogenarian captain at Peel had heard one as a boy, the bellowings of the brute making the ground tremble. Rhys noted that the Manx bull was not of the same breed as the Welsh lake bull, whose visits brought great fertility and an overflow of milk, for in the Isle of Man the tarroo ushtey only begot monsters and strangely formed beasts. W. Walter Gill, in 1929, added the tale of Pharick y Kellya of the Lower Kellya in Dalby, cutting turf on the slope of Cronk yn Irree Lhaa about a hundred years before, who saw a little tarroo-ushtey rise out by the well and grow bigger as it came towards him, and laid on to it with his turf spade until it was nothing but a soft jelly like frog spawn, for these watery creatures dissolve at the touch of iron. Gill also recorded that the water bull had something queer about his ears which came out again in the calves that followed his visits to the farm's cows, the mark by which fairy beasts are known.